Background and aims: Space-occupying lesions (SOLs) of the salivary glands are rare. The aim of this study was to describe the radiographic features which should raise suspicion of an SOL, as detected occasionally in cone-beam-computed-tomography (CBCT) sialography.
Methods: All CBCT sialography scans performed in the maxillofacial imaging center between the years 2013-2018 were retrospectively reviewed for suspected SOL provisional diagnosis. Demographic and clinical data was collected. Radiographic features were rated with a scale of 0-2, independently by two skilled examiners. Following further examinations, the SOLs were divided into 4 main groups: benign, malignant, lymph node and false. The inter-rater agreement was evaluated by Cohen`s kappa.
Results: 500 cases were reviewed, of which 25 (5%) cases were suspected for an SOL and referred for further evaluation. 14 cases were either lost to follow-up or refused to perform further examinations. Full data was available for 11 cases. Cohen`s kappa showed substantial inter-rater agreement. Further investigations of all 11 cases revealed 3 (0.4%) cases to be malignant (marginal zone lymphoma in Sjogren`s syndrome; mucosa-associated lymphoid tissue lymphoma in Sjogren`s syndrome and Burkitt lymphoma), 3 cases to be benign (vascular malformation, granulomatous process and lipoma), 1 case to be a lymph node, and 4 cases to be false. Radiographic features raising suspicion for an SOL were region of no fill, splaying of ducts with a ball-in-hand appearance, displacement of surrounding structures and deviation of main duct. These features were unable to differentiate benign from malignant lesions. In contrast, clinical features including constant and non-mealtime swelling, clear saliva upon milking and a palpable mass were correlated with malignant SOLs.
Conclusion: CBCT sialography is not the method of choice for assessing SOLs, but SOLs may be encountered incidentally and thus care must be taken for careful interpretation of the radiographic findings. Clinical correlation is needed as well as referral for other appropriate imaging modalities and biopsy as needed.
